Earlier this year, I wrote that the experts are sounding the alarm on the H5N1 Bird Flu virus that has, in the past, infected wild and food-producing poultry, dairy cattle, and, at the time, one dairy worker in the U.S.
Since then, the government has increased testing of at-risk workers. 52 human cases have, so far, been identified in the U.S. in several states. All but one of these cases involved those in the dairy and poultry industries.
(Aside: Although the human toll is low, hundreds of herds of dairy cattle and millions of wild birds and poultry livestock have been infected.)
Before anyone yells “The sky is falling!”, all of the documented cases so far in the U.S. are alive and well, No one has required hospitalization, but testing of 115 dairy workers revealed positive results in eight cases. All had extensive contact with cattle, but experienced minimal or no symptoms.
The influenza variant, theoretically, has the potential to be the source of the next pandemic. Some claim it could be many times worse than COVID, pointing to a 50 percent death rate in European cases. This version, or “clade,” in the U.S. is not nearly as lethal, and no human-to-human transmission has been proven. Still, hundreds of herds and flocks have tested positive. Recently, a teenager in Canada has become that country’s first case.
Of course, viruses mutate, and the wrong genetic turn could be reason to worry. A mutation that allows human-to-human transmission would change the whole dynamic. As humans exhibit little immunity against the virus once infected, they could be sitting “ducks” for the Bird Flu.
Symptoms
Symptoms of H5N1 virus are pretty general. The CDC has documented the following in the cases seen so far:
- Eye redness
- Fever
- Cough
- Sore throat
- Runny or stuffy nose
- Muscle aches
- Headaches
- Fatigue
- Difficulty breathing
- Pneumonia requiring hospitalization
Less common symptoms include GI symptoms like diarrhea or nausea and vomiting, or neurological issues like convulsions.
Transmission
Factors like wild bird migrations, especially involving geese and ducks, could worsen the situation. Those making seasonal trips North and South could spread the Bird Flu.
Some researchers expect a Bird Flu pandemic in the future but, at present, the CDC doesn’t consider community-wide outbreaks in the U.S. to be likely. It does believe there’s a “critical lag” in testing workers that suggests more cases exist than previously thought. This could have consequences down the road unless more extensive testing in industry workers is performed.
The CDC recently recommended that farm workers with significant bird flu exposure be tested for H5N1 whether or not they experience symptoms. Sounds simple, just test all the workers? Not so easy, for several reasons. Farmers don’t want their operations stopped if positive cases are identified. Many immigrant workers avoid submitting to blood testing or, really, any interaction with government officials. Besides, if they stay home from work in quarantine, they may not get paid.
Still, testing agricultural workers could be important as the traditional flu season begins. What kind of flu does a person have?
PREVENTION
The CDC also wants the antiviral oseltamivir (Tamiflu) offered to workers who had a high-risk exposure to H5N1-infected animals, especially those who didn’t wear adequate personal protection equipment (PPE). Tamiflu is not just a treatment; it has a preventative effect in those over 1 year of age.
The agency recently updated its recommendations to prioritize more PPE for those in higher risk activities, such as those working in milking parlors or in poultry culling operations. Wearing such gear isn’t mandatory, however. Since milking zones are often hot and humid in spring and summer, most workers shun them or use them improperly.
General recommendations for those who are involved in the poultry and other food-producing livestock industry include:
- Practicing proper and frequent hand hygiene.
- Preparing food properly and safely.
- Avoidance of touching the face, mouth, nose, or eyes when in contact with animals or after using the restroom.
The above is also good advice for general influenza as well. In addition, the general public should:
- Avoid exposure to sick or dead wild or domesticated birds, as well as cattle.
- Avoid exposure to animal droppings and contaminated bedding.
- Avoid drinking raw milk. Pasteurization kills H5N1 viruses. Pasteurized milk is safe to drink.
TREATMENT
Although there is no cure for viral influenza, treatment with oseltamivir (Tamiflu) can give relief from symptoms and speed recovery, and even has a preventative effect in those at high risk of exposure. The key is to begin therapy within two days of the onset of symptoms.
Americans are pandemic-weary at this point, with Ebola, Zika, Chikungunya, Dengue, enterovirus D68, and COVID in the news just in the last decade. After COVID wound down, federal funding for pandemic preparedness was no longer a priority. About 335 million dollars for pandemic issues are earmarked in 2025, well short a one-billion-dollar budget request.
Those with high levels of contact with poultry and cattle may consider influenza vaccination. As winter approaches, most medical resources are being used to produce standard seasonal flu vaccines, but research is promising regarding the bird flu. No H5N1 vaccine, however, is available to the general public in the U.S. Don’t expect the availability of mass quantities of proven-safe bird flu vaccine anytime soon.
Bottom Line
My impression from my last article on this subject hasn’t changed. Despite new cases, no human-to-human transmission has been identified. The grand majority of cases seem to be restricted to workers in the poultry and dairy industries. Also in the grand majority, symptoms have been mild. We must be ever vigilant, however, and take precautions to avoid any type of influenza. Mutations happen; if H5N1 suddenly transmits from human to human, all bets are off.
Joe Alton MD
Dr, Alton
